diff --git a/client/python/pyproject.toml b/client/python/pyproject.toml
index d4e8c08a996..79d7d1eeaa3 100644
--- a/client/python/pyproject.toml
+++ b/client/python/pyproject.toml
@@ -10,7 +10,8 @@ authors = [{ name = "G-Research Open Source Software", email = "armada@armadapro
 
 [project.optional-dependencies]
 format = ["black==23.3.0", "flake8==6.0.0", "pylint==2.17.4"]
-docs = ["sphinx", "sphinx-jekyll-builder", "sphinx-toolbox==3.2.0b1"]
+# note(JayF): sphinx-jekyll-builder was broken by sphinx-markdown-builder 0.6 -- so exclude it
+docs = ["sphinx", "sphinx-jekyll-builder", "sphinx-toolbox==3.2.0b1", "sphinx-markdown-builder<0.6"]
 test = ["pytest==7.3.1", "coverage>=6.5.0", "pytest-asyncio==0.21.0"]
 
 [build-system]
diff --git a/third_party/airflow/pyproject.toml b/third_party/airflow/pyproject.toml
index e9eab1dd64b..47b5c24f767 100644
--- a/third_party/airflow/pyproject.toml
+++ b/third_party/airflow/pyproject.toml
@@ -21,7 +21,8 @@ readme = "README.md"
 [project.optional-dependencies]
 format = ["black==23.3.0", "flake8==6.0.0", "pylint==2.17.4"]
 test = ["pytest==7.3.1", "coverage>=6.5.0", "pytest-asyncio==0.21.0"]
-docs = ["sphinx", "sphinx-jekyll-builder"]
+# note(JayF): sphinx-jekyll-builder was broken by sphinx-markdown-builder 0.6 -- so exclude it
+docs = ["sphinx", "sphinx-jekyll-builder", "sphinx-markdown-builder<0.6"]
 
 [build-system]
 requires = ["setuptools"]